Port tool surface finish help

[Chuckles the Clown]

We always have trouble using MS port tools in that the finish in steels like 4130 or 4140 is not 32 micro.

 

Has anyone had any luck improving surface on porting tools?

 

Care to share?

[jeff]

I have used these tool quite a bit,but not recently.

We had a 304SS job that needed a porting tool.

The finish was really good,at least 32 micro.

What material are yo cutting and what are your current speeds and feeds?

[Tom L]

We've used port-cutters here with very good results.

MS33649-12S 75 RPM @ F.05

32 finish or better in copper nickel and k-monel.

We G81 to .001-.003 above finish with coolant.

M00, (to clear any chips), then G82 / P4000

to finish using moly.

 

HTH

[Chuckles the Clown]

Thanks for the replies

 

We cut inconel and other nasty materials such as monel, but we have more trouble with finishes on 4140 and 4130 than those. Looks like tearing, we tried messing with speeds and feeds, dwells, sped it up, slowed it down, but never get 32 finish or less, we end up polishing.

 

In your post you mentioned using moly...what are you refering to there?

[specv]

moly dee tapping fliud... the best and worst oil you can use

[Tom L]

+1 Pete

moly-dee is some messy stuff. contaminates the

coolant, but we deal with it.

[EZ3PUTT]

We cut a lot of 4140 and do a lot of ports in the stuff. We have All of our 4140 heat treated to 28-32HRc. In the normal condition the stuff is just to soft for us and tends to tear as you mentioned. Turning of the soft stuff is not as bad as milling. I hit 700 SFPM on the lathes and get spectacular finishes.

[Chuckles the Clown]

I agree...we do the same thing when we can. The particular part has 5 ports and turning insn't an option.

 

I will try the tapping compound, but thanks for the suggestions!

[Chuckles the Clown]

I agree...we do the same thing when we can. The particular part has 5 ports and turning insn't an option.

 

I will try the tapping compound, but thanks for the suggestions!

[kinglouie V]

how about run high end on rpm (for material) and end with a dwell?

[CAM-mando]

Chuckles are you using pilot or reamer type ?

 

Reamer type will give best results as the pilot type require clearance and will always be suceptible to chatter.

[chip]

Ever run roller burnishing tools?

 

 

http://www.monaghaninc.com/monagburntools.htm

[mrainey]

Used to do a lot of ports. We got best finishes with carbide-tipped tools rather than the inserted type. High RPM caused a created a problem most of the time. We ran them slow, with a dwell.

[Matthew]

I have not had good success with port tools either. Haven't done a lot of them, but I always end up putting it on a manual mill just to touch them up. I've only had one hole in a setup to do so it didn't take very long. I've thought about getting some end mills ground up with the form of the port cutter and interpolating it, but I haven't had high enough quantities yet to justify it. Also opens up some room for error.

[CAM-mando]

I ran a bunch of ports in the od of some Ti6Al4V parts a couple of months ago. No problems. As mentioned above, a little conservative on the speed. I also use the carbide tipped type. As I mentioned above, but think is worth repeating, I have found the Reamer tip is a must for tougher materials especially. Since the tip of these tools are cutting material, it stabelizes the c'bore portion and will provide better finishes.

 

In contrast the pilot type are designed with clearance between the pilot and the tap drill size so the tool can shake and chatter a bit.

[connormac]

quote:

---

how about run high end on rpm (for material) and end with a dwell?

---

Only if you want it to bark like a dog & end up with a finish that looks like you used a hammer & chisel.

 

Chuckles,

 

I went in like Tom L sugested. I used plain old sulfur oil on the G82 pass. Nasty, but cut way down on tearing and produced a good finish. I also decreased my RPM's on the G82 cycle.

[kinglouie V]

Back!

Back!

[kinglouie V]

Thank you Connormac for correcting my typing to match my train of thought to the old adage of "reduce speed and increase feed"

 

 

then dwell